Hello! Am trying to create a burn wire system for a deep sea drop camera and was wondering if the old potted cable penetrators are depth rated to 500m? I understand that the WetLink penetrators are depth rated to 950m but would like to see what the other options are. Thanks everyone.
Due to the fickle nature of chemical reactions in a variable world, we can’t meaningfully provide an official depth rating for a general-purpose and user-sealed product like a potted penetrator. The depth capacity is dependent on the interface strengths between the potting compound, the cable jacket, and the aluminium walls of the penetrator, which depends on a variety of factors, including
- the materials involved, and their chemical compatibilities
- surface treatment of the cable jacket and penetrator wall
- impurities, dirt, skin oils, etc that reduce bond strength
- temperature and pressure during potting and setting (bubbles?)
- correct seating of cable jacket against penetrator shoulder
- length of bond
- e.g. does the potting compound fill the head and extend into the throat?
It’s also relevant to consider storage and operating conditions, whereby
- high temperatures (e.g. from extended direct sunlight exposure, or hot water) can degrade/weaken potting compound, and may cause thermal stresses from uneven expansion
- strong jerks on the cable may shear the seal
- if a non water-blocked cable gets cut, water can enter through the cable (true of any penetrator)
It’s not impossible for a potted penetrator to withstand significant depths, but unfortunately it’s difficult to ascertain the depth capacity of a given potting without highly controlled installation and operating conditions, or actually testing it.